Bio-Inspired Fabrication of Silver Nanoparticles Using High Altitude Squamulose Lichen Extract and Evaluation of its Antioxidant, Anticandida and Cytotoxic properties

Abstract

Bio-inspired nanoparticle synthesis has attracted substantial interest among the scientific society owing to its eco-friendly and non-toxic nature. In the present study, Silver nanoparticles (AgNPs) were synthesized using high altitude squamulose lichen – Cladonia subradiata and characterized using different techniques. The antioxidant and anticandida activity of AgNPs were evaluated using multiple in-vitro assays. In-silico molecular docking analysis and in-vitro cytotoxic assay was performed to determine the anti-cancer potential of synthesized AgNPs. The results of the spectroscopic studies revealed the successful synthesis of AgNPs and the presence of different functional groups suggesting the involvement of phytocompounds in the reduction and capping of AgNPs. The average size of the AgNPs was 20 nm and predominantly spherical in shape. AgNPs demonstrated excellent DPPH free radicals scavenging activity with an IC50 value of 7.51 ± 0.4 µg/mL. C.albicans was identified as the most susceptible strain from the anticandida studies. Usnic acid and Pulvinic acid exhibited low binding energies and showed excellent inhibition interaction with EGFR lung cancer protein. The in-vitro cytotoxic results were impressive with an IC50 value of 28.75 µg/mL for A549 lung cancer cells treated with AgNPs. Thus, the study demonstrates the effective and non-toxic synthesis of AgNPs using a less explored lichen extract as a promising anticandida and anticancer agent in the field of nano-medicine.